JP2005113511A - Mud improvement method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a mud improvement method capable of continuously carrying out treatment to a dredged mud from dredging to improved soil, increasing efficiency of the treatment of the dredged mud and, at the same time, carrying out the treatment of the dredged mud even if there is no wide space around a dredging site by eliminating a curing space. <P>SOLUTION: A dredging process making the dredged mud as the dredged mud having water content not more than 200% and a process changing into the improved soil having water content not more than 100% enabling the dumping conveyance to carry out by mixing a proper amount of neutral soil conditioner in the middle of conveyance while conveying the dredged mud to agitate and mix with a pipe-line mixer 9 are continuously carried out by using a high concentration mud dredger 1. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a mud improvement method for improving dredged mud removed from swamps, rivers, oceans and the like so that it can be reused.

  For example, if sludge accumulates in swamps, rivers, oceans, etc., it may cause deterioration of water quality, red tide, etc., and in order to prevent or improve such problems, the deposited sludge may be removed with dredging.

  However, removal of the deposited sludge with dredging will generate a large amount of dredged mud, and the dredged mud will have a high moisture content. Processing is absolutely necessary.

  Conventionally, the solidification method of dredged mud is to mix and stir a cement-based solidifying agent to dredged mud with a high water content, solidify it after a predetermined curing period, and then dump it out. (For example, refer to Patent Document 1).

Japanese Utility Model Publication No. 11-343634 (first page)

  By the way, since the above-mentioned conventional solidification treatment method uses a cement-type solidifying agent, a curing period until solidification is required for about one week, and not only the treatment efficiency is extremely bad, but also a space for curing. There is a problem that must be secured.

  In addition, dredged mud with a high water content cannot be dumped as it is, so it is necessary to treat dredged mud near the dredging site. Therefore, a large space must be secured near the dredge site, which is a major factor that makes dredging work difficult.

  Accordingly, an object of the present invention is to enable continuous treatment of dredged mud from dredging to improved soil, increase the treatment efficiency of dredged mud, and eliminate the need for a curing space. By doing so, it is providing the mud improvement method which can process dredged mud even if there is no large space near the dredging site.

  In order to solve the problems as described above, the present invention includes a step of making dredged mud with a water content ratio of 200% or less, and mixing an appropriate amount of a neutral soil improver during the transfer while transferring the dredged mud. Then, a configuration is adopted in which the step of making the soil with improved water content that can be dumped is continuously performed by stirring.

  A gypsum-based soil improver is used as the neutral soil improver, and the soil improver is mixed and stirred at a volume ratio of 10% or less with respect to the dredged mud soil. The moisture content of the improved soil is 100% or less. Can be

  By dredging dredged mud with a high concentration mud dredger, dredged mud with a moisture content of 200% or less can be obtained. After removal, the sludge is stored in a mud storage tank and pumped out from the tank and sent to the mixer. At the same time, a neutral soil conditioner is supplied to the mixer, and the sludge and neutral soil conditioner are mixed and stirred. As a result of this mixing and stirring, the sludge becomes an improved soil having a water content of 100% or less, and this improved soil is ready for dump conveyance.

  According to this invention, while transporting dredged soil with a water content of 200% or less, by mixing and stirring an appropriate amount of a neutral soil improver in the middle of the transfer, continuous to improved soil with a water content ratio capable of dump transportation. As a result of the continuous treatment of dredged mud, the work efficiency is greatly improved, dumping of the improved soil becomes possible, and the use of a neutral soil improver makes the improved soil medium. It can be used effectively as various types of embankment because it has good vegetation as well as use of land for farmland.

  In addition, since dredged mud has been continuously improved to improved soil, the conventional curing period and curing space are no longer necessary, and not only the efficiency of treatment is improved by omitting the curing period, but also the space required for processing. The dredged soil can be treated even if there is no large space near the dredging site.

  Embodiments of the present invention will be described below with reference to the accompanying drawings.

  FIG. 1 shows the overall equipment structure for implementing the mud improvement method. An existing high-concentration mud dredger 1 for dredging mud mud and a first mud storage tank 2 installed on the ground are pumped with a water feed pipe 3 and a ground pump. Connected with pipe 4 and provided with a rotary trommel type or vibrating sieve 5 between the ground pressure feed pipe 4 and the first mud storage tank 2 to remove gravel and dust of 3mmφ or more contained in dredged mud soil. It is supposed to be.

  The first mud storage tank 2 and the second mud storage tank 6 disposed in the vicinity thereof are connected via an underwater sand pump 7 so that a fixed amount of dredged mud soil is stored in the second mud storage tank 6. Then, a pipe mixer 9 is connected to the second mud storage tank 6 via a squeeze pump 8 whose discharge amount is variable, and the mud mud in the second mud storage tank 6 is quantitatively taken out by the squeeze pump 8. Supply to the line mixer 9.

  A storage silo 10 for neutral soil conditioner is installed in the vicinity of the pipeline mixer 9, and the storage silo 10 and the pipeline mixer 9 are made of a variable sub-tank 11, a variable feeder using a rotary feeder and the like. The neutral soil improving agent is supplied to the conduit mixer 9 by connecting the improving agent quantitative supply device 12 and the screw conveyor 13 for supplying the improving agent.

  FIG. 3 shows an example of the pipe mixer 9, in which an inlet 15 for dredged mud clay and an outlet 16 on the outer peripheral surface of the other end are provided on the outer peripheral surface of one end side of the cylindrical casing 14, and the cylindrical casing 14 is assembled inside the cylindrical casing 14. The rotary shaft 17 is driven by a motor 18, and the rotary shaft 17 is provided with a screw 19 at a position corresponding to the inlet 15 and a number of stirring blades 20 at other positions, and a swivel provided at the end on the inlet 15 side. The screw conveyor 13 is connected to the joint 21 via a pressure feed pipe 22, and the rotating shaft 17 is provided along the axial center so as to become a discharge port 24 at the tip 23 of the improving agent passage 23 or the screw 19. Yes.

  The improved soil discharged from the outlet 16 of the pipe line mixer 9 is transported by the belt conveyor 25, loaded into a dump 27 using a heavy machine 26 such as a backhoe, and then transported to a treatment plant.

  Here, as the neutral soil improver, a gypsum-based soil improver is used, and this soil improver is mixed and stirred at a volume ratio of 10% or less with respect to the above-mentioned mud mud soil, and the moisture content of the improved soil is increased. Can be made 100% or less.

  As a specific example of the above-mentioned gypsum-based soil conditioner, “Plaster Rock” sold by “Neutralization Solidification Research Society” in Tamba Co., Ltd. can be exemplified. Combination of calcium oxide 33.80% (wt%), sulfur trioxide 26.03%, ferric oxide 1.55%, aluminum oxide 2.40%, magnesium oxide 4.02%, silicon dioxide 13.68% The solidification principle consists of a primary hydration reaction of solidified gypsum by absorption of hemihydrate gypsum by mixing with dredged soil, followed by a secondary hydration reaction with activated inorganic salts of gypsum. .

  Next, the mud improvement method of this invention is demonstrated.

  As shown in the figure, dredged mud dredged by the high concentration mud dredger 1 is treated by the dredger 1 so that the water content ratio is 200% or less, and the dredged mud described above is pumped to the first mud storage tank 2 installed on the ground. The dredged mud that has been pressure-fed through the pipe 3 and the ground pressure-fed pipe 4 and from which the gravel and dust have been removed by the fluid device 5 is stored in the first mud storage tank 2, and the dredged mud in the first mud storage tank 2 is stored. Is supplied into the second mud storage tank 6 by the sand pump 7, and a constant amount of dredged mud is always stored in the second mud storage tank 6.

  At the same time that the mud mud in the second mud storage tank 6 is quantitatively supplied to the pipe mixer 9 by the squeeze pump 8, the neutral soil conditioner stored in the storage silo 10 is supplied to the mud mud. Supply in a fixed amount.

  The mixing ratio of the neutral soil improver to the dredged mud is 10% or less, preferably 10 to 5%. The dredged mud and the neutral soil improver are stirred and mixed by the pipe mixer 9.

  The pipe mixer 9 feeds the dredged mud supplied from the inlet 15 forward with a screw 19 and stirs the dredged mud sent to the outlet 16 through the casing 14 with a large number of stirring blades 20. The neutral soil conditioner supplied to the passage 23 of the rotary shaft 17 is ejected to the dredged mud from the discharge port 24 located at the tip of the screw 19, and the stirrer blade 20 efficiently converts the dredged mud and the neutral soil conditioner. By thoroughly mixing and agitation, the solidification principle established by the primary hydration reaction of the neutral soil conditioner hemihydrate gypsum by water absorption and the secondary hydration reaction with the activated mineral salts of gypsum started thereafter, The dredged mud is solidified by the action of the neutral soil improver and discharged from the outlet 16 as improved soil having a water content of 100% or less.

  Such improved soil having a moisture content of 100% or less is in a state where the improved soil can be dumped as it is, and is transported to a desired position by the belt conveyor 25 and then loaded on the dump 27 by the heavy machine 26 for processing. Transport to the field.

  As described above, the dredged mud dredged in the high-concentration mud dredger 1 with a water content of 200% or less is quantitatively supplied to the pipe mixer 9, and the dredged mud and neutral soil are improved by the pipe mixer 9. By mixing and stirring the agent, dredged mud can be continuously treated as improved soil with a water content of 100% or less, which eliminates the need for a curing period and a curing space for the improved soil. Not only can the processing efficiency be improved by omitting the period, but also the space required for processing can be extremely reduced, and dredged mud can be processed even if there is no large space near the dredging site.

  Further, by using a neutral soil conditioner, the improved soil becomes neutral soil, and it can be effectively used as various embankments because of good vegetation as well as use of customer land for farmland.

Longitudinal front view showing the entire apparatus for carrying out the mud improvement method of the present invention Same as above Cutaway plan view of the main part of the pipe mixer used in the mud improvement method of the present invention Flowchart diagram of the mud improvement method of the present invention

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 High concentration mud dredger 2 1st mud storage tank 3 Water pressure feed pipe 4 Ground pressure feed pipe 5 Flue device 6 2nd mud storage tank 7 Submersible sand pump 8 Squeeze pump 9 Pipe mixer 10 Storage silo 11 Sub tank 12 Quantification of modifier Supply device 13 Screw conveyor 14 Cylindrical casing 15 Inlet 16 Outlet 17 Rotating shaft 18 Motor 19 Screw 20 Stirring blade 21 Swivel joint 22 Pressure feed pipe 23 Passage 24 Discharge port 25 Belt conveyor 26 Heavy machine 27 Dump

Claims (2)

  Moisture ratio that can be dumped by mixing and stirring a suitable amount of neutral soil conditioner while transferring the dredged mud soil while transferring the dredged mud soil to a dredged mud soil with a water content ratio of 200% or less. A method for improving mud soil characterized by continuously performing the process of making improved soil.   A gypsum-based soil improver is used as the neutral soil improver, and the soil improver is mixed and stirred at a volume ratio of 10% or less with respect to the dredged mud soil. The moisture content of the improved soil is 100% or less. The mud improvement method according to claim 1, wherein:

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